Biased lever arm switch



June 1965 R. M. 'DYKSTERHOUSE BIASED LEVER ARM SWITCH Filed Jan. 25, 1962 ELE IE United States Patent 3,187,148 BIASED LEVER ARM SWITCH Robert M. Dyksterhouse, Charlevoix, Mich., assignor, by mesne assignments, to Circuit Controls Corporation, Petoskey, Mich., a corporation of Michigan Filed Jan. 25, 1962, Ser. No. 168,637 1 Claim. (Cl. 200-464) The present invention relates to a safety switch and more particularly to a switch particularly useful in a setting wherein a mechanical interference linkage engages the operating arm of the switch to cause selective movement in the switch elements. Still more particularly the switch of the present invention is ball operated through a radial or arcuate pathway providing selected contact as between ball and lead contact elements. The ball is propellel in the selected pathway by an actuating arm element pivoted from an axis located transverse to the plane of ball movement and on a radius of the ball path. The arm is biased to a predetermined position by thrust acting on the arm. The bias is overcome as overcoming force is applied to a lever, for example, by providing a bell crank extension from the axis of the arm. A two-part case is utilized, one part thereof being made of conductive material and the other part thereof being formed from electrical insulating material and carrying a conductive insert defining a portion of the pathway of the ball. Thus, a V- groove pathway is defined as between the two case members and the conductive case cooperates with the conductive insert of the insulating case to accomplish, with cooperation of the conducting ball, the selected opening and closing of electrical circuits. Hence, the struc ture is peculiarly amenable to ground return usage as found in automotive applications.

The swtich has found best application as a safety switch for tailgate window actuator disconnect applications in the construction of stationwagons. It is easily coordinated with mechanical functions such as locks and door handles to provide selected energization and deenergization of, for example, an electrical window actuator. The necessity for devising such a switch is apparent when it is realized that costly damage can occur to Windows which are accidentally raised during the opening of the tailgate since energization cranks the windows completely out of its guides or beyond the closing limits of the tailgate. By means of the present switch, tailgate windows are operable so long as the gate is closed, but are rendered inoperable upon opening of the tailgate.

Apart from this particular application the unique form of the switch is easily adapted to a variety of mechanical disconnect functions where motion establishes the position for switch energization or de-enerzigation. Collaterally the switch is adaptable to a variety of simple ground return installations. The switch mechanism is very simple and is hence amenable to rapid and economical fabrication. The design of the switch assures excellent switch accuracy without impossible and expensive tolerance requirements.

General description In general, the switch of the present invention comprises a switch case in which an arcuate V-groove pathway is defined. In the V-groove pathway spaced apart conducting areas are defined. A guide conducting ball is positioned in the arcuate pathway so as to be movable into and out of contact with the conducting portions. A resilient bias is applied to the ball which urges it into a preselected position in the arcuate pathway. As this bias is overcome by the application of overcoming pressures, the ball is moved in the arcuate pathway and accomplishes selected energization by becoming the conducting means as between the two spaced apart conducting portions. This structure is easily built up from mating switch case halves which define therebetween the switch cavity and each provides one-half of the arcuate V-groove. Where one-half of the case is made of conducting material and the other half of the case is non-conductive electrically, then a simple conductive insert in the non-conducting portion of the pathway renders the switch structure amenable to ground return application. The switch case also defines a pivot transverse of the plane defined by the arcuate pathway. A ball carriage is operatively connected to the pivot so that the are described by the ball carriage is in parallel arcuate register with the pathway. The carriage carries the captive ball, and with a lever arm extending from the case, provides a lever structure capable of moving the ball in the pathway. A spring provides ball contact pressures in the groove acting between the ball and carriage. A resilient bias is provided to act upon the carriage biasing it into a pre-selected position at one end of the arcate pathway. Application of overcoming pressures to the extending lever arm overcomes the carriage bias allowing movement of the carriage and hence, the ball. Release of the overcoming pressures caused the return of carriage and ball. Where the lever and carriage are fabricated from conducting material a simple nylon or other insulating sleeve separating spring and ball from the conductive lever provides avoidance of arcing in the spring and lever structure.

In the drawing:

FIGURE 1 is a perspective view of a switch in accord with the present invention illustrating the extreme simplicity of the case and the simple pivotal arrangement for the actuating lever.

FIGURE 2 is an exploded perspective view of the switch as shown in FIGURE 1 indicating the mating case halves together defining the spring bias receptacle, the arcuate V-groove and the pivot provisions.

FIGURE 3 is a plan view of the switch of the present invention with one of the case halves removed indicating the assembled inter-relationship between ball carriage, case, and carriage bias.

FIGURE 4 is a fragmetnal perspective front view of the ball carriage assembly and indicating the bias within the switch cavity assuring carriage return and the backup spring for selected ball positioning.

Specific description Referring to the drawing and more specifically to FIGURE 1, thereof, a switch 11, in accord with the present invention is shown fully assembled. The switch 11 is seen to comprise an upper switch case half 12 and a lower switch case half 13, the latter provided with suitable mounting flanges, such as the perforated flange ear 14. This flange 14 will be understood as providing means for securing the switch 11 in a selected position as for example to a body structure of an automotive door or the like. The mounting flange 14 may be altered as required by specific installation provisions. The lower case half 13 is clinched to the upper case half by tabs 15 in spaced arrangement about the switch 11. A pivot 16 is provided transversely through the mating case halves 12 and 13. An electrical connector 17 extends from the switch case 18 defined upon assembly of the two switch case halves 12 and 13. An actuating lever 19 extends from the case 18 and, as will be appreciated, is operative on the pivot 16 in the manner of a bell crank with the case 18 providing suitable journalling.

By reference to FIGURE 2 the simplicity of the switch 11 is better understood. The upper half case 12 has been removed to reveal its internal configuration as it cooperates with the lower case half 13 between which halves a switch cavity 2% is defined. The cavity is defined on one side by arcuate V-groove elements 211 and 22 extending from the case halves 12 and 13, respectively. The V-groove elements 21 and 22, when assembled, provide a V-groove pathway therebetween providing a track for the ball 23. The ball 23 is retained in partially captive form in the ball carriage assembly 24 comprising a part of the lever 19. The pivot 16 extends upward through and is journalled by the upper case 12. A shoulder 25 coaxial with the pivot 16 and depending from the carriage 24 is journalled in the lower case half 13 and through the opening 26 provided through the case half 13. Hence, upon asembly, the lever 19 and carriage 24 is journalled in the case halves 12 and 13 through the openings 26 (half 13) and 27 (half 12 best shown in FIGURE 1) and the concentric barrel portion 28 of the carriage 24, coaxial with pivot 16, is buttressed by the rounded extension 29 of the upper case half 12. Tangential wings 3t and 31 extending from the rounded extension 29 provide adequate travel limiting stops shouldering against the carriage 2d at its extremes of travel. The lower case 13 defines a receptacle opening 32 as a portion of the switch cavity 2h. This receptacle opening 32, bounded by walls 33, 34 and 35 provides an entrapment or pocket for the resilient bias controlling the return function of the carriage 24, and the resilient bias is represented in the FIGURE 2 by a compression spring 36 and ball-ended spring guide 37. The spring 36 thus nests in the pocket provided by the cavity 32 and butts against the wall 35 and against the guide 37 thereby urging ball end 35; into the socket 39 provided in the wall of the carriage 24 and applying a guided resilient bias to the carriage 24. The walls 33 and 34 limit the movement of the spring 35 and the ball-socket connection at the carriage 24 provides an excellent swivelling control connection as between resilient bias and carriage 2 The carriage 24 is also provided with a recessed extension 40 which extends radially from the pivot 16. A back up spring 41 is inserted in a recess -58 (see FIGURE 4) axially defined in the extension 44!. The spring 41 is of the compression type and urges the ball 23 into the V-groove formed by the V-groove elements 21 and 22 when the case 18 is assembled. The compression on the ball 23 is relatively light so as not to interfere with rolling contact as between ball and V-groove shoulders 21 and 22. A contactor insert 42 is provided in the V-groove pathway 21. The insert 42 extends through the case half 12 and is made a part of the connector 17. The insert is secured by the clinch tab 43 and nests in the shoulder element 21 of the V-groove so as to provide an unbroken pathway for the rolling of the ball 23. A similar outer clinch is accomplished by use of tabs 44 and 45 shown best in FIGURE 1. V

In FIGURE 3 the assembled interrelationship of elements is shown with the case half 12 removed. The ball 23, obedient to the movement of lever 19 is moved in the carriage 24 along the V-groove shown defined solely by the single V-groove element 22. In such action the lever 19 is pivotal on the pivot 16 transversely provided in respect to the plane defined by the V-groove. The receptacle 32 provides guide pocketing for the spring 36 and the spring 36 with guide .37 provides a resilient bias against the carriage 24 and lever 19 urging the ball 23 to one extreme of travel. As will be seen case walls 46 and 47 provide stop limits to the carriage 24.

In FIGURE 4 the carriage 24 lever 19 assembly is better understood. The cylindrical recess 48 in the extension 40 is shown into which is inserted an insulated sleeve 4-9 and back-up spring 41. The sleeve 49 provides captive control over the ball 23 while the ball 23 is in contact with the V-groove and eliminates arcing when Q the lever 13 and carriage 24 are formed from conducting material. The relationship of the resilient bias spring 36 and guide rod 37 is better understood as the ball end 38 extends to engage the socket 339 in the carriage 24 in swivel relationship.

The described switch is amenable to a variety of easily understood adaptations. As shown the case half 12 is made of insulating material having good dielectric properties, as for example, nylon. The case half 13 is die cast from metal and is hence conductive. Then the insert 4-3 provided in the V-groove element 21 of case half 12 is also conductive, as for example, copper, brass, bronze, silver, beryllium-copper. Switch closing contact is made when movement of the conducting ball 23 in the V-groove defined by the V-groove elements 21 and 22 establishes bridging contact between case half 13 and insert strip 43. In this instance the switch is of the ground return type and current flow is between insert 43 and case 13 through ball 23. Only a single insert 43 is required and this also provides an integral connection 17 for electrical wiring. When used as a tailpipe safety switch, the ball 23 is biased by spring 36 into position as shown in FIGURE 3 thus avoiding closing of the switch 11 until such time as the lever 19 is moved to place the ball 23 in contact with the insert strip or contactor 43 and overcoming the resilient bias 36. Such closing of the switch 11 occurs only by engagement with associated mechanical elements upon closure of the tailgate, hence providing a master disconnect control over, say, window actuating means until full closure is accomplished. As shown the lever 19 and carriage 24 are integrally cast from metal, for example, die cast metal, and the insulating sleeve 49 serves to avoid arcing as between carriage 24 and ball 23 or spring 41. As will be understood the illustrated device is thus of the ground return type wherein the case element 13 is grounded, as for example, to an automotive frame. Conversion from ground return is simple, as for example, by placing a registering insert 43 in the V-groove element 22 and extending its connector prong 17 through the case half 13. In this instance both case halves 12 and 13 are formed from insulating material. The arm lever 19 and carriage 24. may in such instances remain as constructed or may be made from insulating resin material. In either case the ball 23 performs its identical contact in movement along the V-groove.

As will also be appreciated detenting provision 50 may be provided in the V-groove shoulder 21 as shown in case element 12. Similarly, the form of the insert strip 43 may be varied to provide selective positions of contact where plural position control is desired. In addition, the location of the strip 43 can be selectively varied in accord with particular usage.

In operation the switch 11 has proved very satisfactorilyin test and actual usage. The elements are relatively rough in dimensions making possible economical die or mold forms without serious impairment of switch accuracy. The operational simplicity of the switches provides long switch life with trouble free performance. The contacts are wear compensating and the rolling character of the conducting ball 23 provides substantially antifriction movement at the interphase between ball and contact areas. Assembly of the switch 11 is very simple and easily adaptable to unskilled labor.

Having thus described my invention in a complete embodiment thereof, a wide variety of modifications, adaptations, and improvements therein will be readily appreciated by those skilled in the art and such modifications, adaptations, and improvementsare intended to be included within the present invention limited only by the scope of my hereinafter appended claim.

I claim:

In a safety switch for coordination with mechanical disconnect, the combination comprising:

(a) a first switch case shell half of insulating material including a cavity therein defining one-half of an arcaute groove path;

(b) a second switch case shell half of conducting material including a cavity therein defining one-half of an arcuate groove path, said second switch case shell half mating with said first switch case shell half so as to form a switch case defining an arcuate groove path therein;

(c) a conductive insert provided through said first shell half and forming a portion of the arcuate groove path defined in said case;

(d) a transverse pivot through said case halves;

(e) a bell crank lever pivotal on said pivot and extending into said switch case and extending externally therefrom;

(f) a ball carriage assembly carrying a conducting ball, said assembly being fixedly attached to the portion of said lever extending into said case, said ball carriage assembly being selectively movable within said case in response to selected movement of said lever; said conducting ball held captive within said arcuate groove path by said ball carriage assembly,

References Cited by the Examiner UNITED STATES PATENTS 1,257,784 2/ 18 Beirns 200164 1,796,000 3/31 Cheney 20084 2,511,069 6/50 Lawson et al 20011 X 2,868,906 1/59 Soreng 20011 X FOREIGN PATENTS 763,853 2/ 34 France.

BERNARD A. GILHEANY, Primary Examiner. 

